Refactor scripts pathing to run from repo base path

[MikeLippincott]

          Seeing the number of `cd` commands made me concerned that this might be challenging to maintain (there are also `cd`'s in the scripts). Would it make sense to remove the nested `cd`'s in the script files sourced here to make directory control "single-sourced"? Generally, where you can, I recommend running all scripts as though they were run from the same location (instead of from within the nested directories), referencing full paths from the context of the project throughout. I bring this up out of care for the development overhead which multiple directory location / relocations can cause.

Originally posted by @d33bs in #8 (comment)